| /* |
| * Copyright (c) 2005, 2006, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| package javax.swing.plaf.nimbus; |
| |
| import java.awt.GraphicsConfiguration; |
| import java.awt.Image; |
| import java.lang.ref.ReferenceQueue; |
| import java.lang.ref.SoftReference; |
| import java.util.Arrays; |
| import java.util.Iterator; |
| import java.util.LinkedHashMap; |
| import java.util.Map; |
| import java.util.concurrent.locks.ReadWriteLock; |
| import java.util.concurrent.locks.ReentrantReadWriteLock; |
| |
| /** |
| * ImageCache - A fixed pixel count sized cache of Images keyed by arbitrary set of arguments. All images are held with |
| * SoftReferences so they will be dropped by the GC if heap memory gets tight. When our size hits max pixel count least |
| * recently requested images are removed first. |
| * |
| * @author Created by Jasper Potts (Aug 7, 2007) |
| */ |
| class ImageCache { |
| // Ordered Map keyed by args hash, ordered by most recent accessed entry. |
| private final LinkedHashMap<Integer, PixelCountSoftReference> map = |
| new LinkedHashMap<Integer, PixelCountSoftReference>(16, 0.75f, true); |
| // Maximum number of pixels to cache, this is used if maxCount |
| private final int maxPixelCount; |
| // Maximum cached image size in pxiels |
| private final int maxSingleImagePixelSize; |
| // The current number of pixels stored in the cache |
| private int currentPixelCount = 0; |
| // Lock for concurrent access to map |
| private ReadWriteLock lock = new ReentrantReadWriteLock(); |
| // Reference queue for tracking lost softreferences to images in the cache |
| private ReferenceQueue<Image> referenceQueue = new ReferenceQueue<Image>(); |
| // Singleton Instance |
| private static final ImageCache instance = new ImageCache(); |
| |
| |
| /** Get static singleton instance */ |
| static ImageCache getInstance() { |
| return instance; |
| } |
| |
| public ImageCache() { |
| this.maxPixelCount = (8 * 1024 * 1024) / 4; // 8Mb of pixels |
| this.maxSingleImagePixelSize = 300 * 300; |
| } |
| |
| public ImageCache(int maxPixelCount, int maxSingleImagePixelSize) { |
| this.maxPixelCount = maxPixelCount; |
| this.maxSingleImagePixelSize = maxSingleImagePixelSize; |
| } |
| |
| /** Clear the cache */ |
| public void flush() { |
| lock.readLock().lock(); |
| try { |
| map.clear(); |
| } finally { |
| lock.readLock().unlock(); |
| } |
| } |
| |
| /** |
| * Check if the image size is to big to be stored in the cache |
| * |
| * @param w The image width |
| * @param h The image height |
| * @return True if the image size is less than max |
| */ |
| public boolean isImageCachable(int w, int h) { |
| return (w * h) < maxSingleImagePixelSize; |
| } |
| |
| /** |
| * Get the cached image for given keys |
| * |
| * @param config The graphics configuration, needed if cached image is a Volatile Image. Used as part of cache key |
| * @param w The image width, used as part of cache key |
| * @param h The image height, used as part of cache key |
| * @param args Other arguments to use as part of the cache key |
| * @return Returns the cached Image, or null there is no cached image for key |
| */ |
| public Image getImage(GraphicsConfiguration config, int w, int h, Object... args) { |
| lock.readLock().lock(); |
| try { |
| PixelCountSoftReference ref = map.get(hash(config, w, h, args)); |
| // check reference has not been lost and the key truly matches, in case of false positive hash match |
| if (ref != null && ref.equals(config,w, h, args)) { |
| return ref.get(); |
| } else { |
| return null; |
| } |
| } finally { |
| lock.readLock().unlock(); |
| } |
| } |
| |
| /** |
| * Sets the cached image for the specified constraints. |
| * |
| * @param image The image to store in cache |
| * @param config The graphics configuration, needed if cached image is a Volatile Image. Used as part of cache key |
| * @param w The image width, used as part of cache key |
| * @param h The image height, used as part of cache key |
| * @param args Other arguments to use as part of the cache key |
| * @return true if the image could be cached or false if the image is too big |
| */ |
| public boolean setImage(Image image, GraphicsConfiguration config, int w, int h, Object... args) { |
| if (!isImageCachable(w, h)) return false; |
| int hash = hash(config, w, h, args); |
| lock.writeLock().lock(); |
| try { |
| PixelCountSoftReference ref = map.get(hash); |
| // check if currently in map |
| if (ref != null && ref.get() == image) { |
| return true; |
| } |
| // clear out old |
| if (ref != null) { |
| currentPixelCount -= ref.pixelCount; |
| map.remove(hash); |
| } |
| // add new image to pixel count |
| int newPixelCount = image.getWidth(null) * image.getHeight(null); |
| currentPixelCount += newPixelCount; |
| // clean out lost references if not enough space |
| if (currentPixelCount > maxPixelCount) { |
| while ((ref = (PixelCountSoftReference)referenceQueue.poll()) != null){ |
| //reference lost |
| map.remove(ref.hash); |
| currentPixelCount -= ref.pixelCount; |
| } |
| } |
| // remove old items till there is enough free space |
| if (currentPixelCount > maxPixelCount) { |
| Iterator<Map.Entry<Integer, PixelCountSoftReference>> mapIter = map.entrySet().iterator(); |
| while ((currentPixelCount > maxPixelCount) && mapIter.hasNext()) { |
| Map.Entry<Integer, PixelCountSoftReference> entry = mapIter.next(); |
| mapIter.remove(); |
| Image img = entry.getValue().get(); |
| if (img != null) img.flush(); |
| currentPixelCount -= entry.getValue().pixelCount; |
| } |
| } |
| // finaly put new in map |
| map.put(hash, new PixelCountSoftReference(image, referenceQueue, newPixelCount,hash, config, w, h, args)); |
| return true; |
| } finally { |
| lock.writeLock().unlock(); |
| } |
| } |
| |
| /** Create a unique hash from all the input */ |
| private int hash(GraphicsConfiguration config, int w, int h, Object ... args) { |
| int hash; |
| hash = (config != null ? config.hashCode() : 0); |
| hash = 31 * hash + w; |
| hash = 31 * hash + h; |
| hash = 31 * hash + Arrays.deepHashCode(args); |
| return hash; |
| } |
| |
| |
| /** Extended SoftReference that stores the pixel count even after the image is lost */ |
| private static class PixelCountSoftReference extends SoftReference<Image> { |
| private final int pixelCount; |
| private final int hash; |
| // key parts |
| private final GraphicsConfiguration config; |
| private final int w; |
| private final int h; |
| private final Object[] args; |
| |
| public PixelCountSoftReference(Image referent, ReferenceQueue<? super Image> q, int pixelCount, int hash, |
| GraphicsConfiguration config, int w, int h, Object[] args) { |
| super(referent, q); |
| this.pixelCount = pixelCount; |
| this.hash = hash; |
| this.config = config; |
| this.w = w; |
| this.h = h; |
| this.args = args; |
| } |
| |
| public boolean equals (GraphicsConfiguration config, int w, int h, Object[] args){ |
| return config == this.config && |
| w == this.w && |
| h == this.h && |
| Arrays.equals(args, this.args); |
| } |
| } |
| } |